Dictionary of Electrical Terms, Abbreviations, and Acronyms

A B C D E F G H I J K L M N O P Q R S T U V WXYZ

Note: Words in bold within the text of a definition indicate other definitions in this dictionary.

1-CP: 1-month coincident peak for year.

12-CP: 12-month coincident peak average.

6X16: Abbreviation used to refer to the on-peak period for electricity sales. That is, 16 hours per day for 6 days per week.

6X8+24: Abbreviation used to refer to the off-peak period for electricity sales. That is, 8 hours per day for 6 days per week, plus all day Sunday.

7X24: Abbreviation used to refer to a continuous period for electricity sales. That is, 24 hours per day for 7 days per week.

$/kW/month: Monthly charge for capacity (i.e., dollars per kilowatt (kW) per month).

Access Charge: A fixed tariff rate that recovers the portion of a utility's transmission revenue requirement not recovered through the variable Usage Charge.

ACE: Area Control Error - The instantaneous difference between generation and load in a utility Control Area. The Control Area Operator's SCADA system monitors ACE and minimizes it using Regulation. This parameter is used to determine a control area's control performance with respects to its' impact on system frequency.

ACH: Automated Clearinghouse

Acid Rain: Also called acid precipitation or acid deposition, acid rain is precipitation containing harmful amounts of nitric and sulfuric acids formed primarily by nitrogen oxides and sulfur oxides released into the atmosphere when fossil fuels are burned. It can be wet precipitation (rain, snow, or fog) or dry precipitation (absorbed gaseous and particulate matter, aerosol particles or dust). Acid rain has a pH below 5.6. Normal rain has a pH of about 5.6, which is slightly acidic. The term pH is a measure of acidity or alkalinity and ranges from 0 to 14. A pH measurement of 7 is regarded as neutral. Measurements below 7 indicate increased acidity, while those above indicate increased alkalinity.

Acre Foot: Unit of hydraulic volume measurement used to describe a quantity of storage in a reservoir, or the amount of water used for agricultural purposes. The volume covering one acre to a depth of one foot.

• 1 acre foot = 325,829 gallons
• 1 acre foot = 43,560 ft³
• 1 acre foot = 1233.47 meters³

ACSR: Aluminum Conductor, Steel Reinforced. A type of conductor used in overhead transmission lines, that contains an arrangement of aluminum and steel strands. The aluminum strands provide the current carrying capacity while the steel strands provide reinforcing strength and resistance to sag when heated due to heavy electrical loading and/or weather conditions.

Actual Imbalance: A deviation between last accepted generation and load schedule compared to the actual generation and load delivered.

Actual Peak Load Reductions: The actual reduction in annual peak load (measured in kilowatts) achieved by consumers that participate in a utility DSM program. It reflects the real changes in the demand for electricity resulting from a utility DSM program that is in effect at the same time the utility experiences its annual peak load, as opposed to the installed peak load reduction capability (i.e., Potential Peak Load Reduction). It should account for the regular cycling of energy efficient units during the period of annual peak load.

Adverse Hydro (Adverse Water Conditions): Water Conditions limiting the production of hydroelectric power either from low or restricted water supply or reduced gross head.

AGC: Automatic Generation Control - Automatic Generation Control is equipment that automatically adjusts a Control Area's generation from a central location to maintain its interchange schedule plus frequency bias.

Aggregator: An entity responsible for planning, scheduling, accounting, billing and settlement for energy deliveries from the aggregator's portfolio of Sellers (generators, purchases) and/or Buyers (loads or sales).

AHP: Available Hydro Power - The actual amount of hydroelectric power available during a given time period from SLCA/IP powerplants, depending on hydrological conditions. AHP may be less than, equal to, or greater than SHP.

Airway Marker Ball: A round, colored ball, usually aviation orange, attached to the conductors or overhead ground wire for daytime marking. Available in various sizes from 20” diameter and larger.

Allowance for Funds Used During Construction (AFUDC): A noncash item representing the estimated composite interest costs of debt and a return on equity funds used to finance construction. The allowance is capitalized in the property accounts and included in income.

A-LP: Animas LaPlata Project, a Bureau of Reclamation water project located near Durango in southwestern Colorado. A-LP is a participating project of the CRSP.

Alternating Current: Term applied to an electric current or voltage that reverses its direction of flow at regular intervals and has alternately positive and negative values, the average value of which over a period of time is zero. Compare Direct Current.

Ambient Temperature: The temperature of the surrounding cooling medium, such as gas or liquid, which comes into contact with the heated parts of the apparatus.

Ammeter: A meter placed in a circuit that measures the number of amperes of electric current flowing in a circuit.

Ampere (A): The unit of measurement of electric current. It is proportional to the quantity of electron flow through a conductor past a given point in one second. It is the unit current produced in a circuit by one Volt applied across a resistance of one Ohm.

AMWG: Adaptive Management Work Group

Ancillary Services: Ancillary services are those services necessary to support the transmission of energy from resources to loads while maintaining reliable operation of the Transmission Provider's transmission system in accordance with good utility practice.
Four real-power ancillary services -

Regulation: Generator is on-line, utilizing automatic generation control, and the unit can respond quickly to control center requests for up and down movements.

Spinning reserve: Generator is on-line and synchronized to the grid. It can increase output immediately in response to a major outage and can reach full capacity within 16 minutes.

Supplemental reserve: Same as spinning reserve, but the unit doesn't have to respond immediately. Thus, unit can be off-line, but capable of reaching full capacity within 15 minutes.

Replacement reserve: Same as supplemental reserve, but response time is stretched to as long as 60 minutes.
Source: Eric Hirst

The six required Ancillary Services as defined in FERC Orders No. 888 and 889 are:

• scheduling, system control and dispatch service - schedules the amount of energy to be delivered, assigning load and ensuring operational security, among other tasks;
• reactive supply and voltage control from generation sources service - maintains correct voltage through adjustment to generator output;
• energy imbalance service - provides energy correction for any hourly mismatch between a transmission customer's energy supply and demand served;
• regulation and frequency response service - follows the moment-to-moment variations in the demand or supply in the control area;
• operating spinning reserve service - provides immediate back-up service from a reserve unit to serve load in case of a system contingency;
• operating supplemental reserve service - serves load when a contingency exists; not available immediately to serve load but can be available within a short time.

Annual Effects: The total effects in energy use (measured in megawatthours) and peak load (measured in kilowatts) caused by all participants in the DSM programs that are in effect during a given year. It includes new and existing participants in existing programs (those implemented in prior years that are in place during the given year) and all participants in new programs (those implemented during the given year). The effects of new participants in existing programs and all participants in new programs should be based on their start-up dates (i.e., if participants enter a program in July, only the effects from July to December should be reported). If start-up dates are unknown and cannot be reasonably estimated, the effects can be annualized (i.e., assume the participants were initiated into the program on January 1 of the given year). The Annual Effects should consider the useful life of efficiency measures, by accounting for building demolition, equipment degradation and attrition.

Annual Transmission Costs: The total annual cost of the Transmission System shall be the amount specified in Schedule 1 until amended by the Transmission Provider or modified by the Commission.

Annunciator: A visual signaling device indicating one or more conditions that exist or have existed in a associated circuit.

Anthracite: A hard, black lustrous coal, often referred to as hard coal, containing a high percentage of fixed carbon and low percentage of volatile matter.

Arcing: The process of current leaping the gap from one electrode to another.

Armor Rod: Protective pre-formed wires wrapped around aluminum conductor to prevent damage at point of support. Also used to repair minor conductor damage.

Arrester: A power system device which limits the voltage of a surge applied to its terminals and interrupts any follow current. Commonly called a surge arrester, a surge diverter, or a lightning arrester.

Ash: Impurities consisting of silica, iron, alumina, and other noncombustible matter that are contained in coal. Ash increases the weight of coal, adds to the cost of handling, and can affect its burning characteristics. Ash content is measured as a percent by weight of coal on an "as received" or a "dry" (moisture-free, usually part of a laboratory analysis) basis.

Asset: An economic resource, tangible or intangible, which is expected to provide benefits to a business.

Assisted Irrigation Investment: (from RA6120.2) "Assisted irrigation investment" means the portion of construction costs of Federal Reclamation projects which are allocated to the irrigation purpose and are assigned pursuant to legal authorization for repayment from the revenues of the power system.

ATC: Available Transmission (or Transfer) Capacity

Automatic Generation Control (AGC): The regulation of electric generator power output within a control area in response to changes in system frequency, time, error, and tie-line loading, so as to maintain the scheduled system frequency and the established interchanges with other areas.

Autotransformer: A transformer which uses a common winding for both the primary and secondary sides. This gives it distinct advantages, both in economy and size, over two-winding power transformers when the transformation ratio is small. For example, an auto-transformer would be used to step up voltages from 230 kilovolts to 345 kilovolts whereas a two-winding power transformer would be used to boost voltages from 13.8 kilovolts to 230 kilovolts.

Auxiliary Equipment (Generating Station): Accessory equipment necessary for generating station operations. This would include pumps, stokers, fans, pulverizers, etc.

Auxiliary Power Supply (Generating Station): The power required to operate generating station auxiliary equipment.

Available but not Needed Capability: Net capability of main generating units that are operable but not considered necessary to carry load, and cannot be connected to load within 30 minutes.

Average Hydro (Average Water Conditions): Precipitation and runoff conditions which provide water for hydroelectric power generation approximating the most often recurring (mean) amount and distribution over a long time period, usually the entire period of record.

Average Revenue per Kilowatt-hour: The average revenue per kilowatt-hour of electricity sold by sector (residential, commercial, industrial, or other) and geographic area (State, Census division, and National), is calculated by dividing the total monthly revenue by the corresponding total monthly sales for each sector and geographic area.

Aviation Marker Ball: A round, colored ball, usually aviation orange, attached to the conductors or overhead ground wires for daytime marking. Available in various sizes from 9-inch diameter and larger.

Avoided Costs: The costs an electric utility would otherwise incur to generate power if it did not purchase electricity from another source.

Backbone Transmission System: The principal portion of a transmission system to which other lines connect.

Balancing Account: An account set up to allow periodic balancing of financial transactions that, under normal course of business, do not result in a zero balance of cash inflows and outflows within a specified accounting period.

Balancing Energy Supply: Energy not scheduled in advance that is required to meet energy imbalances in real-time. This energy is supplied by generators under the system operator's control, providing spinning and non-spinning reserves, replacement reserves, and regulation, and other generators able to respond to the system operator's request for more or less energy.

Bare Hand: Live Line Maintenance (see Live Line Maintenance).

Barrel: A volumetric unit of measure for crude oil and petroleum products equivalent to 42 U.S. gallons.

Base Bill: A charge calculated by multiplying the rate from the appropriate electric rate schedule by the consumption level.

Baseload: The minimum amount of electric power delivered or required over a given period of time at a steady rate.(Contrast to Peak Load)

Baseload Generation Capacity: The generating equipment normally operated to serve loads on an around-the-clock basis. Those generating facilities within a utility system which are operated to the greatest extent possible to maximize system mechanical and thermal efficiency and minimize system operating costs.

Baseload Plant (or Unit): A plant, usually housing high efficiency steam-electric units, which is normally operated to take all or part of the minimum load of a system, and which consequently produces electricity at an essentially constant rate and runs continuously. These units are operated to maximize system mechanical and thermal efficiency and minimize system operating costs.

Baseload Power: Power generated to meet the level of electrical demand during all hours of a time period

Basin Fund: Upper Colorado River Basin Fund

Bbl: The abbreviation for barrel.

BBS: Bulletin Board System (electronic data access through FERC)

Bcf: The abbreviation for 1 billion cubic feet.

Betterment: A substantial enlargement or improvement of existing structures, facilities, or equipment by replacement or improvement of parts without replacement of a complete unit of property, which has the effect of extending the useful life of the property, increasing its capacity, lowering its operating cost, or otherwise adding to its worth through the benefit it can yield.

Bilateral Contract: An agreement for the purchase and the sale of energy products and services.

Biomass: Any organic material not derived from fossil fuels. The rules defines “biomass” as a plant materials that are obtained from cultivation, or harvested from naturally occurring vegetation without significant resource depletion. A variety of organic fuel sources which can either be processed into synthetic fuels or burned directly to produce steam or electricity.

Bituminous Coal: The most common coal. It is dense and black (often with well-defined bands of bright and full material). Its moisture content usually is less than 20 percent. It is used for generating electricity, making coke, and space heating. Comprises five groups classified according to the following ASTM Specification D388-84, on a dry mineral-matter-free (mmf) basis for fixed-carbon and volatile matter and a moist mmf basis for calorific value.

LV =Low volatile bituminous coal

MV=Medium volatile bituminous coal

HVA=High volatile A bituminous coal

HVB=High volatile B bituminous coal

HVC=High volatile C bituminous coal

Black Start: See Startup Service

Blackout: The disconnection of the source of electricity from all the electrical loads in a certain geographical area brought about by an emergency forced outage or other fault in the generation/transmission/distribution system servicing the area. A blackout could also be caused by intentional load drops if adequate generation is not available to meet the load. [See Rolling (Rotating) Blackout]

Blackout, Rolling (Rotating): Controlled recurring outages across a region designed to prevent a system disturbance when power demand is greater that the available generation or transmission capacity. "Rolling" or "Rotating" refers to the method that system operators use - disconnecting a certain load area for a time period, then reconnecting it and disconnecting another load area in a subsequent time period.

Boiler: A device for generating steam for power, processing, or heating purposes or for producing hot water for heating purposes or hot water supply. Heat from an external combustion source is transmitted to a fluid contained within the tubes in the boiler shell. This fluid is delivered to an end-use at a desired pressure, temperature, and quality.

Broker: An entity acting as an agent for others in negotiating contracts, purchases, or sales of electrical energy or services without owning any transmission or generation facilities. Such business or party does not take ownership for the power transacted.

Brownout: An intentional reduction of loads in an area by the partial reduction of electrical voltages which results in lights dimming and motor driven devices losing efficiency.

Brush: A stationary conductor, usually carbon, held in contact with a moving conductor. Typically used in electric motors or generators.

Btu (British Thermal Unit): A standard unit for measuring the quantity of heat energy equal to the quantity of heat required to raise the temperature of 1 pound of water by 1 degree Fahrenheit. The fuel content of one btu is roughly equivalent to a kitchen match.

Bulk Delivery Point: A substation that receives power delivered at high voltage. Transformers at these points lower the voltage for power distribution.

Bundle, Conductor: Two or more conductors per phase, in a power transmission line.

Bureau Of Reclamation: Agency within the Department of Interior responsible for operating and maintaining certain hydroelectric powerplants and certain irrigation facilities. BOR and USBR are both abbreviations for the Bureau of Reclamation.

Bus: Generally, a conductor, or group of conductors, that serves as a common connection for two or more circuits. In substations, specifically a conductor, usually rigid, which interconnects equipment of the same voltage. Then, by extension of usage, any rigid conductor.

Busbar: An electrical conductor in the form of rigid bars, located in switchyard or powerplants, serving as a common connection for two or more electrical circuits.

Cable Miles: The total length of separately sheathed cables, expressed in miles, regardless of the number of conductors contained in a single sheath. For pipe-type cables, it is the total single-conductor mileage.

CAISO: California Independent System Operator - A state chartered organization in California charged with ensuring the reliability of the electric power system.

Calorie: A unit of heat energy equal to the amount of heat that will raise the temperature of one gram of water one degree Celsius.

Capability: The maximum load that a generating unit, generating station, or other electrical apparatus can carry under specified conditions for a given period of time without exceeding approved temperature and stress limits.

Capability Curve: A curve drawn to show the limits of reactive and kilowatt loads that a generator can tolerate without overheating or becoming unstable.

Capability Margin (Reserve Margin): The difference between net system capability and system maximum load requirements (peak load). It is the margin of capability available to provide for scheduled maintenance, emergency outages, system operating requirements, and unforeseen loads. On a regional or national basis, it is the difference between aggregate net system capability of the various systems in the region or nation and the sum of system maximum (peak) loads without allowance for time diversity between the loads of several systems. However, within a region, account is taken of diversity between peak loads of systems that are operated as a closely coordinated group.

Capability, Emergency: The gross unit or plant output corresponding to the net demonstrated capability, and includes auxiliary use power. Units or plants may be operated at these ratings only in an emergency.

Capability, Gross System: The total net generating station capability of a system at a stated period of time (usually at the time of the system's maximum load), plus capability available at such time from other sources through firm power contracts.

Capability, Peaking: Generating capability normally designed to use only during the maximum load period of a designated time interval.

Capacitor (Cap.): A device to store an electrical charge. It usually consists of two conductors separated by a non conductor (dielectric) such as glass, paper, air, oil, or mica. A capacitor will not pass direct current; its impedance for alternating current frequencies is inversely proportional to frequency.

Capacitor Bank: A grouping of capacitors used to maintain or increase voltage in power lines and to improve system efficiency by reducing inductive losses which waste energy.

Capacity: The amount of electric power delivered or required for which a generator, turbine, transformer, transmission circuit, station, or system is rated by the manufacturer. The rate of delivery of electricity measured in kilowatts or megawatts.

Capacity, Assured System: The dependable capacity of system facilities available for serving system load after allowance for required reserve capacity, including the effect of emergency interchange agreements and firm power agreements with other systems.

Capacity, Base Load: see Baseload Generation Capacity

Capacity Charge: An element in a two-part pricing method used in capacity transactions (energy charge is the other element). The capacity charge, sometimes called Demand Charge, is assessed on the amount of capacity being purchased. The capacity charge is sometimes expressed in units of $/kW/month .

Capacity, Contingent: Capacity sold to customers with the understanding that the service may be unavailable under certain conditions.

Capacity Component: Part of a firm-power rate; shown in the power repayment study (PRS) as a dollar per kW per year charge. Billed on a dollar per kW per month basis. Applied each billing period to each kW which each contractor is entitled to by contract.

Capacity, Dependable: The load-carrying ability of a station or system under adverse conditions for the time interval and period specified when related to the load characteristics to be supplied. Dependable capacity of a system includes net firm power purchases.

Capacity Factor: The fraction or percentage of total energy delivered from a resource over a period of time, divided by the maximum that could have been delivered if the resource was used at its maximum capacity over the entire period.

Capacity, Hydraulic: The rating of a hydroelectric generating unit or the sum of such ratings for all units in a station or stations.

Capacity, Installed: The total of the capacities as shown by the nameplates of similar kinds of apparatus such as generating units, turbines , synchronous condensers, transformers, or other equipment in a station or system.

Capacity, Nameplate: The nominal rated capacity of a generating unit or other similar apparatus. The term gives an indication of the approximate generating capacity of the unit, but in many cases the unit is capable of generating on a continuous basis substantially more than the nameplate capacity.

Capacity, Overload: The maximum load that a machine, apparatus, or device can carry for a specified time period under specified conditions when operating beyond its nameplate rating but within the limits of the manufacturer's guarantee and within the safe limits determined by the owner. For example, most of the generators installed in newer hydroelectric plants have a continuous overload capacity of 115 percent of the nameplate capacity.

Capacity, Peaking: Generating equipment normally operated only during the hours of highest daily, weekly, or seasonal loads. Some generating equipment may be operated at certain times as peaking capacity and at other times to serve loads on a round-the-clock basis.

Capacity, Purchased: The amount of energy and capacity available for purchase from outside the system.

Capacity Rate:See Capacity Charge.

Capacity, Reserve Generating: Extra generating capacity available to meet unanticipated power demands or to generate power in the event of generation loss resulting from scheduled or unscheduled outages of regularly used generating capacity.

Capacity, Reserve System: The difference between dependable system capacity, including net firm power purchases, and the actual or anticipated peak load for a specified period.

Cold: Thermal generating units available for service but not maintained at operating temperature.

Hot: Thermal generating units available, up to temperature and ready for service, although not actually in service.

Spinning: Generating units connected to the bus and ready to take load or operating below rated level.

Capacity, Thermal: The rating of a thermal electric generating unit or the sum of such ratings for all units in a station or stations.

Capital (Financial): The line items on the right side of a balance sheet that include debt, preferred stock, and common equity. A net increase in assets must be financed by an increase in one or more forms of capital.

Cascading Outages: A connected series of uncontrolled outages that resembles dominos falling one after another.

Cathode Ray Tube (CRT): The picture tube on a TV set. Technically a tube in which an electron beam can be focused on luminescent particles on a screen and varied in position and intensity to produce a visible pattern.

CBM: Capacity Benefit Margin

Ccf: One hundred cubic feet. Used as a measure of residential natural gas usage.

CDP: Customer Displacement Power. A replacement option under the Amendment to SLCA/IP firm electric service contract.

cfs: Cubic feet per second

• 1 cfs for 1 minute = 449 gallons
• 1 cfs for 24 hours = 646,272 gallons
• 1 cfs for 24 hours = 1.983 acre feet
• 1 cfs for 7 days = 13.881 acre feet
• 1 cfs for 30 days = 59.5 acre feet
• 1 cfs for 1 year = 724 acre feet

Charge, Demand: That portion of the charge for electric service based upon the customer's billing demand under an applicable rate schedule or contract.

Circuit: A conductor or a system of conductors through which electric current flows or is intended to flow.

Circuit Miles of Electric Line: The total length in miles of separate circuits, not including customer's services, whether one, two, three, four or more conductors per circuit.

Circuit Breaker: Generally, any switching device that is capable of closing under normal load conditions or interrupting an electrical circuit under overload or short circuit conditions.

Circuit Recloser: A line protective device which interrupts momentary line faults. In addition, it restores power automatically when the fault is cleared.

Class Of Service: Type of power sold to customers (i.e., firm power and energy, non-firm power and energy, peaking power - with or without energy, emergency service, maintenance service, fuel replacement service, etc.).

Clearance: A statement with documentation from the operations supervisor to the job supervisor declaring that all equipment to be worked on has been de-energized and has been isolated from hazardous sources of energy.

Clearance Requirements: Distances required between conductors of various voltages and the ground; also, the distance required between the line and trees, buildings, and other objects on, above, or immediately adjacent to the right-of-way.

Closed (versus Open): When referring to a circuit breaker or other switching device, closed means that the switch contacts are together, the switch is on and current has a flow path. OPEN means the switch contacts are apart, the switch is off, and current cannot flow.

CME: Capitalized movable equipment.

Coal: A black or brownish-black solid combustible substance formed by the partial decomposition of vegetable matter in the absence of air. The rank of coal, which includes anthracite, bituminous coal, subbituminous coal, and lignite, is based on fixed carbon, volatile matter, and heating value. Coal rank indicates the progressive alteration from lignite to anthracite. Lignite contains approximately 9 to 17 million Btu per ton. The contents of subbituminous and bituminous coal range from 16 to 24 million Btu per ton and from 19 to 30 million Btu per ton, respectively. Anthracite contains approximately 22 to 28 million Btu per ton.

Co-generation: Producing both electric energy and steam from various energy sources.

Cogenerator: A generating facility that produces electricity and another form of useful thermal energy (such as heat or steam) used for industrial, commercial, heating, or cooling purposes. To receive status as a qualifying facility (QF) under the Public Utility Regulatory Policies Act (PURPA), the facility must produce electric energy and "another form of useful thermal energy through the sequential use of energy," and meet certain ownership, operating, and efficiency criteria established by the Federal Energy Regulatory Commission (FERC). (See the code of Federal Regulations, Title 18, Part 292.)

Coil: One or more wound insulated conductors arranged to produce an electromagnetic force. Used in electro-mechanical protective relays and rotating electrical machinery in power systems as well as devices which provide inductances in electronics and power systems.

Coincidental Demand: The sum of two or more demands that occur in the same time interval.

Coincidental Peak Load: The sum of two or more peak loads that occur in the same time interval.

Coke (Petroleum): A residue high in carbon content and low in hydrogen that is the final product of thermal decomposition in the condensation process in cracking. This product is reported as marketable coke or catalyst coke. The conversion factor is 5 barrels (42 U.S. gallons each) per short ton.

Cold Shutdown: Refers to the situation when the boiler working fluid or the coolant water in a nuclear reactor is below the boiling point and the pressure is reduced to atmospheric levels.

Collbran: Collbran Project, a Federal multipurpose water project located in western Colorado near Grand Junction.

Collection Ring: A metal ring suitably mounted on an electric machine that conducts current into and out of the rotating member.

Combined Cycle: An electric generating technology in which electricity is produced from otherwise lost waste heat exiting from one or more gas (combustion) turbines. The exiting heat is routed to a conventional boiler or to a heat recovery steam generator for use by a steam turbine to produce electricity. This process increases the efficiency of the electric generating unit.

Combined Cycle Unit: An electric generating unit that consists of one or more combustion turbines and one or more boilers with a portion of the required energy input to the boiler(s) provided by the exhaust gas of the combustion turbine(s).

Combined Pumped-Storage Plant: A pumped-storage hydroelectric power plant that uses both pumped water and natural streamflow to produce electricity.

Commercial: The commercial sector is generally defined by electric utilities as nonmanufacturing business establishments, including hotels, motels, restaurants, wholesale businesses, retail stores, and health, social, and educational institutions. The utility may classify commercial service as all consumers whose demand or annual use exceeds some specified limit. The limit may be set by the utility based on the rate schedule of the utility.

Commercial Operation: Commercial operation begins when control of the loading of the generator is turned over to the system dispatcher.

Commission: The Federal Energy Regulatory Commission.

Committed Load: The load that has been accepted to be served either in the day-ahead or hour-ahead bidding process.

Common Costs: Costs that are incurred jointly for two or more types of operations and are subsequently allocated to each such operation (electric, gas, water, etc.) usually on the basis of the relative percentages of utility plant, revenue, or use of space.

Common Plant: Utility Plant used by a utility company which renders more than one utility service, such as electric and gas, to such an extent and in such a manner as to render segregation impractical, as would be the case with a garage housing electric and gas utility trucks, or where one facility such as coal handling or water treatment is provided to serve the combined boiler plant.

Commutator: In an electrical motor or generator, a ring of insulated copper segments connected to the rotating armature windings, and on which brushes make contact.

Composite Rate: The rate for commercial firm power and is the total annual revenue requirement for capacity and energy divided by the total annual energy sales. It is expressed in mills/kWh and used for comparison purposes.

Condenser: A large heat exchanger designed to cool exhaust steam from a turbine below the boiling point so that it can be returned to the heat source as water. (In a pressurized water reactor, the water is returned to the steam generator. In a boiling water reactor, it returns to the reactor core.) The heat removed from the steam by the condenser is transferred to a circulating water system and is exhausted to the environment, either through a cooling tower or directly into a body of water. A condenser is also another name for a Capacitor.

Conductor: The wire cable strung between transmission towers through which the electric current flows. More generally, any object (wire, cable, bus) that conducts electric current.

Conductor, Bundled: Two or more conductors per phase of a transmission line. Bundling conductors allows each phase of a transmission line to conduct more current than would a single conductor.

Conductor, Single: One conductor used per phase.

Conduit Bank: A length of one or more underground conduits or ducts (whether or not enclosed in concrete) designed to contain underground cables. A gallery or cable tunnel for power cables is generally treated as conduit bank for property reporting purposes.

Conduit Bank Miles: Miles of conduit bank, regardless of number of conduits or ducts, of all sizes and types, and including manholes and handholes.

Connection: The physical connection (e.g. transmission lines, transformers, switch gear, etc.) between two electric systems permitting the transfer of electric energy in one or both directions.

Conservation and Other DSM: This Demand-Side Management category represents the amount of consumer peak load reduction at the time of system peak due to utility programs that reduce consumer load during many hours of the year. Examples include utility rebate and shared savings activities for energy efficient appliance installation, lighting and electrical machinery, and weatherization materials. In addition, this category includes all other Demand-Side Management activities, such as thermal storage, time-of-use rates, fuel substitutions, measurement and evaluation, and any other utility-administered Demand-Side Management activity designed to reduce demand and/or electricity use.

Constant Current Transformer: A transformer which, when supplied from a constant potential source, automatically maintains a constant current in its secondary under varying load conditions.

Constraints: Physical and operational limitations in electrical power transfer through transmission facilities. Physical, hydrological, operational, and environmental limitations in electrical power generation at hydroelectric facilities.

Construction Work In Progress (CWIP): The balance shown on a utility's balance sheet for construction work not yet completed but in process. This balance line item may or may not be included in the rate base.

Consumer: A customer who purchases power for personal use.

Consumption (Fuel): The amount of fuel used for gross generation, providing standby service, start-up and/or flame stabilization.

Contingency: The unexpected failure or outage of a system component, such as a generator, transmission line, circuit breaker, switch, or other electrical element. A contingency also may include multiple components, which are related by situations leading to simultaneous component outages.

Contingency Reserve: The portion of Operating Reserve - Spinning and Supplemental that is allocated to respond to Disturbances.

Contingency Reserve Restoration Period: The time after the end of the Disturbance Recovery Period in which Contingency Reserves must be re-established fully.

Contract Demand: The amount of power (in kilowatts) that an electric service supplier agrees to make continuously available for delivery to a particular consumer and that the consumer agrees to purchase.

Contract Price: Price of fuels marketed on a contract basis covering a period of one or more years. Contract prices reflect market conditions at the time the contract was negotiated and therefore remain constant throughout the contract life or are adjusted through escalation clauses. Generally, contract prices do not fluctuate widely.

Contract Rate Of Delivery (CROD): Firm capacity (kW) the electric service supplier agrees to have available for delivery. It may or may not be accompanied by energy. Synonymous with Contract Demand.

Contract Receipts: Purchases based on a negotiated agreement that generally covers a period of one or more years.

Control Area: An electric power system or combination of electric power systems, bounded by interconnection metering and telemetry, to which a common automatic control scheme is applied in order to:

1. match, at all times, the power output of the generators within the electric power system(s) and capacity and energy purchased from entities outside the electric power system(s), with the load in the electric power system(s);
2. maintain, within the limits of Good Utility Practice, scheduled interchange with other Control Areas;
3. maintain the frequency of the electric power system(s) within reasonable limits in accordance with Good Utility Practice;
4. and provide sufficient generating capacity to maintain operating reserves in accordance with Good Utility Practice.

Control Center: A station from which one or more powerplants are remotely controlled. See also Control Room.

Controller: A device or group of devices that serves to govern, in some predetermined manner, the electric power delivered to the apparatus to which it is connected. Sometimes also referred to as a demand controller.

Control Room: The center where a powerplant is operated, monitored, and controlled (Federal requirements call for a minimum of two licensed operators on duty at all times in a nuclear powerplant control room.) See also Control Center.

Conventional Fuels: The fossil fuels: coal, oil, and natural gas.

Conventional Hydroelectic Plant: A hydroelectric plant that utilizes stream flow only once as it passes downstream, as opposed to a pumped-storage plant which recirculates all or a portion of the streamflow in the production of power.

Converter: A device that changes alternating current power to direct current power or vice versa, or changes one frequency to another.

Converter Station: The assemblage of equipment used to convert alternating current to direct current or vice-versa in a power system.

Coolant: A fluid, usually water, used to cool a nuclear reactor and transfer heat energy. The water also moderates, or slows down, the neutrons used for the fissioning of uranium.

Cooling System: An energy efficiency program promotion aimed at improving the efficiency of the cooling delivery system, including replacement, in the residential, commercial, or industrial sectors.

Cooling Tower: A heat exchanger designed to cool water that was used to cool exhaust steam exiting the power plant turbines. Cooling towers transfer exhaust heat into the air instead of into a body of water.

Cooperative Electric Utility: An electric utility legally established to be owned by and operated for the benefit of those using its service. The utility company will generate, transmit, and/or distribute electrical power to a specified service area not being serviced by another utility. Such ventures are generally exempt from Federal income tax laws. Most electric cooperatives have been initially financed all or in part by loans from the Rural Utilities Services, U.S. Department of Agriculture.

Coordination: The practice by which two or more interconnected electric power systems augment the reliability of bulk electric power supply by establishing planning and operating standards; by exchanging pertinent information regarding additions, retirements, and modifications to the bulk electric power supply system; and by jointly reviewing these changes to assure that they meet the predetermined standards.

Corona: A luminous electrical discharge on a transmission line. Corona appears when the air adjacent to the conductor ionizes due to the applied potential exceeding a certain value. It can be seen as bluish tufts or streamers surrounding the conductor, and generally a hissing sound can be heard. Transmission line corona varies with atmospheric conditions, being more intense during wet weather on A.C. lines. On D.C. lines, audible noise occurs during clear dry weather.

Cost: The amount paid to acquire resources, such as plant and equipment, fuel, or labor services.

Cost Evaluation Period: (from RA6120.2) "Cost evaluation period" means a period of time during which estimates of future costs and revenues may be modified to reflect changing conditions, normally 5 years.

Cost Recovery Criteria: (from RA6120.2) The current rates for a power system will be adequate if, and only if, a power repayment study indicates that:
a. The expected revenues are at least sufficient to recover annually, except for a possible initial short transition period:

1. All costs of operating and maintaining the power system during the year in which such costs are incurred; plus,
2. The cost of acquiring power through purchase and/or exchange agreements, the costs for transmission services, and other costs during the year in which such costs are incurred; plus,
3. Expensed interest on the unamortized investment in Federal power facilities in the year for which the interest charges are assessed, except that recovery of the annual interest expense may be deferred in unusual circumstances for short periods of time; plus,
4. Interest and amortization of revenue bonds where PMAs are authorized to issue such bonds.

b. In addition to the recovery of the above costs on a year-by-year basis, the expected revenues are at least sufficient to recover:

1. Each dollar of power investment at Federal hydroelectric generating plants within 50 years after they become revenue producing, except as otherwise provided by law: plus,
2. Each annual increment of Federal transmission investment within the average service life of such transmission facilities or within a maximum of 50 years, whichever is less; plus,
3. The cost of each replacement of a unit of property of a Federal power system within its expected service life up to a maximum of 50 years; plus,
4. Each dollar of assisted irrigation investment within the period established for the irrigation water users to repay their share of construction costs; plus,
5. Other costs such as payments to basin funds, participating projects or States.

Cost Shifting: A cost transfer from one customer class to another, or from one utility to another. This is considered good when costs are being shifted from you to someone else, and bad when they are being shifted from someone else to you.

CPS - Control Performance Standard: CPS defines a standard of minimum control performance. Each control area is to have the best operation above this minimum that can be achieved within the bounds of reasonable economic and physical limitations. Each control area shall monitor its performance on a continuous basis against two standards: CPS1 and CPS2.

• CPS1 - Control Performance Standard 1: Over a year, the average of the clock-minute averages of a control area's ACE shall be less than a specific limit. This limit is a constant derived from a target frequency bound reviewed and set as necessary by the NERC Resources Subcommittee.
• CPS2 - Control Performance Sstandard 2: The average ACE for each six ten-minute period during the hour (i.e., 10, 20, 30, 40, 50 and 60 minutes after the hour) must be within specific limits referred to as L10.

CREDA: Colorado River Energy Distributors Association

Critical Head or Design Head: The head at which the full-gate output of the hydro turbine equals the name-plate generator capacity.

Critical Hydro Period: Period when the limitations of hydroelectric power supply due to water conditions that are most critical with respect to system load requirements.

CROD: See Contract Rate Of Delivery.

Crossarm: The crossing member(s) of a wood pole or steel tower which support the insulators for the conductor.

CRSP: Colorado River Storage Project, a Federal multipurpose water project with facilities located in the upper Colorado River basin states of Arizona, Colorado, New Mexico, Utah, and Wyoming.

CRSP Act: Act of April 11, 1956, ch. 203, 70 Stat. 105, as amended, 43 U.S.C. 620-6200.

CRSP-MC: The Colorado River Storage Project - Management Center; Western office located in Salt Lake City, UT.

CT: see Current Transformer

CT/VT: Current transformers/ voltage transformers

CUP: Central Utah Project, a Bureau of Reclamation water project located in (you guessed it) central Utah. CUP is a participating project of the CRSP.

Current (Electric): A flow of electrons in an electrical conductor. The strength or rate of movement of the electricity is measured in amperes. A generic term usually modified by an adjective (i.e., AC or DC), the amount of electrical charge flowing through a conductor, as compared to Volts , which is the force that drives the electrical charge.

Current Transformer (CT): A small transformer used to convert high currents to low currents. Used to produce a signal that can be measured by meters, relays, or control equipment.

Customer/Account: An entity or person which purchases and is billed for power and energy and other utility related services some time during the period under consideration.

Customer Brochure: A document prepared for public distribution explaining the background and purpose of the rate proposal.

Cycle: In one cycle of alternating electric current, the current goes from zero potential or voltage to a maximum in one direction, back to zero, then to a maximum in the other direction, and then back to zero. A complete sequence of a wave pattern that recurs at regular intervals. The number of cycles occurring in one second is the frequency of the wave. (Direct current [DC] does not fluctuate from positive to negative and hence cycles or frequency can apply only to alternating current [AC].)

Cycling Units: Units which operate with rapid load changes, frequent starts and stops but generally at somewhat lower efficiencies and higher operating costs than base load plants. These units are generally either former base-load units relegated to cycling units or newly built units at a lower megawatt rating which require less capital investment per unit of output than required for base load units. Contrast with Base Load Unit/Station.

Day-Ahead Market: The forward market for the supply of electrical power at least 24 hours before delivery to Buyers and End-Use Customers.

DCS: Disturbance Control Standard - Disturbance Control Standard is part of the Control Performance Standards. DCS is designed to judge the performance of a Control Area following a reportable disturbance, by evaluating the use of the Control Area's Contingency Reserves.

Dead-End Tower: See Tower, Dead-End

Declining Block Rate: A pattern of unit charges within a customer class that assesses a lower unit charge on additional blocks of demand and/or energy purchases as usage increases.

Degree Day: A unit measuring the extent to which the outdoor mean (average of maximum and minimum) daily dry bulb temperature falls below (in the case of heating) or rises above (in the case of cooling) an assumed base. The base is normally taken as 65° F for heating and cooling unless otherwise designated. One degree-day is counted for each degree of deficiency below (for heating) or excess over (for cooling) the assumed base, for each calendar day on which such deficiency or excess occurs.

Delivering Party: The entity supplying the capacity and/or energy to be transmitted at Point(s) of Receipt.

Demand: In economics usage, the quantity of a product that will be purchased at a given price at a particular point in time. In an electric utility context, the rate at which electric energy is delivered to or by a system over any designated period of time.

Demand, Annual Maximum: The greatest of all demands or the load under consideration which occurred during a prescribed demand interval in a calendar year.

Demand, Annual System Maximum: The greatest demand on an electric system or any of its parts over any prescribed interval of time in a given calendar year.

Demand, Average: The demand on, or the power output of an electric system or any of its parts over any interval of time, as determined by dividing the total number of kilowatt-hours by the number of units of time in the interval

Demand, Billing: The demand upon which billing to a customer is based, as specified in a rate schedule or contract. It may be based on the contract year, a contract minimum, or a previous maximum and, therefore, does not necessarily coincide with the actual measured demand of the billing period.

Demand Charge: That portion of the charge for electric service based upon the electric capacity (kW or KVA) consumed and billed on the basis of billing demand under and applicable rate schedule.

Demand, Coincident: The sum or two or more demands which occur in the same demand interval.

Demand Factor: The ratio of the maximum demand of a system, or part of a system, to the total connected load of the system, or part of the system, under consideration.

Demand, Instantaneous Peak: The maximum demand at the instant of greatest load, usually determined from the readings of indicating or graphic meters.

Demand, Integrated: The demand usually determined by an integrating demand meter or by the integration of a load curve. It is the summation of the continuously varying instantaneous demands during a specified demand interval.

Demand Interval: The period of time during which the electric energy flow is integrated in determining demand, such as 60-minute, 30-minute, or instantaneous.

Demand, Non-coincident: The sum or two or more individual demands which do not occur in the same demand interval. Meaningful only when considering demands within a limited period of time, such as day, week, month, heating or cooling season, and usually for not more than a year.

Demand-Side Management: The planning, implementation, and monitoring of utility activities designed to encourage consumers to modify patterns of electricity usage, including the timing and level of electricity demand. It refers only to energy and load-shape modifying activities that are undertaken in response to utility-administered programs. It does not refer to energy and load-shape changes arising from the normal operation of the marketplace or from government-mandated energy efficiency standards. Demand-Side Management (DSM) covers the complete range of load-shape objectives, including strategic conservation and load management, as well as strategic load growth.

Demand-Side Management Costs: The costs incurred by the utility to achieve the capacity and energy savings from the Demand-Side Management Program. Costs (expenditures) incurred by consumers or third parties are to be excluded. The costs are to be reported in nominal dollars in the year in which they are incurred, regardless of when the savings occur. Program costs include expensed items incurred to implement the program, incentive payments provided to consumers to install Demand-Side Management measures, and annual operation and maintenance expenses incurred during the year. Utility costs that are general, administrative, or not specific to a particular Demand-Side Management category are to be included in "other" costs.

Department of Energy (DOE): An agency established in 1977 by the Department of Energy Organization Act to consolidate the major Federal energy functions into one cabinet level department that would formulate a comprehensive, balanced national energy policy. DOE is responsible for a variety of regulatory, research, and marketing programs related to energy production and use. Numerous laboratories and test sites are involved in these projects.

Design Voltage: The nominal voltage for which a line or piece of equipment is designed. This is a reference level of voltage for identification and not necessarily the precise level at which it operates.

Designated Agent: Any entity that performs actions or functions on behalf of the Transmission Provider, an eligible Customer or the Transmission Customer required under the Tariff.

Direct Access: The right for a Generator to engage in a Bilateral Contract with a Buyer.

Direct Access Generation: The generation output which is used to meet the demand of Bilateral Contracts.

Direct Access Demand: The energy consumption met under Bilateral Contracts who are eligible to select their supplier of electric power.

Direct Current (DC): Term applied to an electric current or voltage which may have pulsating characteristics, but which does not reverse direction.

Direct Load Control: Refers to utility programs that can interrupt consumer load at the time of annual peak load by direct control of the utility system operator by interrupting power supply to individual appliances or equipment on consumer premises. This type of control usually involves residential consumers. Direct Load Control excludes Interruptible Load and Other Load Management effects. (Direct Load Control, as defined here, is synonymous with Direct Load Control Management reported to the North American Electric Reliability Council on the voluntary Office of Energy Emergency Operations Form OE-411, "Coordinated Regional Bulk Power Supply Program Report," with the exception that annual peak load effects are reported here and seasonal (i.e., summer and winter) peak load effects are reported on the OE-411).

Direct Utility Cost: A utility cost that is identified with one of the DSM program categories (i.e., Energy Efficiency, Direct Load Control, Interruptible Load, Other Load Management, Other DSM Programs, Load Building).

Disconnecting Switch: A power system device used to open a circuit in which only a negligible amount of current, or no current is flowing. Disconnecting switches are manually or motor operated, and are used to isolate relatively unloaded equipment. Air is the usual insulating medium between the contacts in the open position.

Dispatch: The operating control of an integrated electric system to 1) assign generation of specific generating stations and other sources of supply to effect the most reliable and economical supply as the total of the significant area loads rises or falls; 2) Control operations of high-voltage lines, substation, and equipment; 3) operate the interconnect; and 4) schedule energy transactions with other interconnected electric utilities.

Dispatcher: One of a number of people at a Dispatch Center who monitor and control a power system. At the Western control centers, responsibilities of the dispatchers include the following:

1. Operation of the Automatic Generation Control equipment to regulate the loading of the generators in the Federal powerplants to help maintain scheduled System Frequency and the scheduled power interchange with other utilities.
2. The source of authority for issuance of all electrical Clearances on the Western system for safe maintenance and repair of equipment.
3. The location and isolation of system trouble and dispatching of maintenance forces to expedite repair of facilities and restoration of service, for security of the system.
4. Surveillance and maintenance of the transmission voltage schedules.
5. The Western employee in charge of the system switching function at a Dispatch Office.

Dispatch Center: A room located in a transmission or distribution System Control Center which contains the display and control devices used by Dispatchers to monitor and control the power system.

Dispatching: The operating control of an integrated electric system involving operations such as:

1. The assignment of load to specific generating station and other sources of supply to effect the most reliable and economical supply as the total of the significant area loads rises or falls.
2. The control of operations with maintenance of high-voltage lines, substations, and equipment.
3. The operation of principal tie lines and switching.
4. The scheduling of energy transactions with connecting electric utilities.

Distillate Fuel Oil: A general classification for one of the petroleum fractions produced in conventional distillation operations. It is used primarily for space heating, on-and-off-highway diesel engine fuel (including railroad engine fuel and fuel for agriculture machinery), and electric power generation. Included are Fuel Oils No. 1, No. 2, and No. 4; and Diesel Fuels No. 1, No. 2, and No. 4.

Distribution: The act or process of distributing electric energy from convenient points on the transmission or bulk power system to consumers. Also a functional classification relating to that portion of utility facilities used for the purpose of delivering electric energy from convenient points on the transmission system to consumers, or to expenses relating to the operation and maintenance of distribution plant.

Distribution Line: One or more circuits of a distribution system on the same line of poles or supporting structures, operating at relatively low voltage compared with transmission lines.

Distribution Panel: An electric panel with circuit breakers which energizes the other panels or circuits.

Distribution System: In power system usage, the transport of electricity to ultimate usage points such as homes and industries directly from nearby generators or from interchanges with higher voltage transmission networks which transport bulk power over longer distances from large generation centers.

Disturbance: Any occurrence that adversely affects normal power flow in a system, such as lightning surge on a line, or a short circuit.

Disturbance Recovery Criterion: The ACE (or its equivalent) behavior that must be observed within the Disturbance Recovery Period to be compliant with the Disturbance Control Standard.

Disturbance Recovery Period: The time after the start of a Disturbance in which the Disturbance Recovery Criterion shall be met for compliance with the NERC Disturbance Control Standard (DCS).

Diversity: The characteristic of a variety of electric loads whereby individual maximum demands usually occur at different times. Diversity among customer loads results in diversity among the loads of distribution transformers, feeders, and substations, as well as between entire systems. Also known as Load Diversity.

Diversity Exchange: An exchange of capacity or energy, or both, between systems whose peak loads occur at different times of the day or seasons of the year.

Diversity Factor: The ratio of the sum of the noncoincident maximum demands of the various subdivisions of a system, or part of a system, to the maximum demand of the whole system, or part under consideration.

DOE: United States Department of Energy.

DOE Order RA 6120.2: An order dealing with power marketing administration financial reporting and rate-making procedures. See RA6120.2.

Double Circuit: The placing of two separate electrical circuits (for alternating current, each consisting of three separate conductor or bundles of conductors) on the same row of towers.

DPR: Definite Plan Report, a Bureau of Reclamation document outlining the development of a water project.

Drawdown: The distance that the water surface of a reservoir is lowered from a given elevation as the result of the withdrawal of water for generation or irrigation.

DSM: See Demand Side Management

DSWR: The Desert Southwest Region of the Western Area Power Administration.

Dual Rate, Double Rate or Two Rate Watthour Meter: A watthour meter with two registers constructed so that the on-peak and off-peak energy (kilowatthours) will be indicated on a separate set of dials. The switch from one register to the other is controlled by an internal time switch or by an external signal that may be actuated by a local device or by a device located at a remote location. Carryover may be accomplished by battery or spring storage or photocell synchronization.

Dynamic Transfer: The provision of the real-time monitoring, telemetering, computer software, hardware, communications, engineering, energy accounting (including inadvertent interchange), and administration required to implement a Dynamic Schedule, Pseudo-Tie or Supplemental Regulation Service.

EA: See Environmental Assessment

Easement: The right, privilege, or interest obtained by Western through condemnation or legal conveyance to construct, maintain, and operate transmission facilities within a tract of land (see Right-of-Way).

Economic Dispatch: The centralized coordinated decision to use generating resources to serve load in the most economic manner.

Eddy-Current Loss: Loss in the iron core of a transformer due to currents being induced in and flowing around core. Also induced in conductors where it causes heating.

EHV: See Extra High Voltage

EIS: See Environmental impact statement.

Electric Capacity: The rated continuous load-carrying ability, expressed in megawatts (MW) or megavolt-amperes (MVA) of generation, transmission, or other electrical equipment.

Electric Energy: The generation or use of electric power by a device over a period of time, expressed in kilowatt-hours (kWh), megawatt-hours (MWh), or gigawatt-hours (GWh).

Electric Plant (Physical): A facility containing prime movers, electric generators, and auxiliary equipment for converting mechanical, chemical, and/or fission energy into electric energy.

Electric Rate: The unit prices and the quantities to which they apply as specified in an electric rate schedule or sales contract.

Electric Rate Schedule: A statement of the electric rate and the terms and conditions governing its application, including attendant contract terms and conditions that have been accepted by a regulatory body with appropriate oversight authority.

Electric Utility: A corporation, person, agency, authority, or other legal entity or instrumentality that owns and/or operates facilities within the United States, its territories, or Puerto Rico for the generation, transmission, distribution, or sale of electric energy primarily for use by the public and files forms listed in the Code of Federal Regulations, Title 18, Part 141. Facilities that qualify as cogenerators or small power producers under the Public Utility Regulatory Policies Act (PURPA) are not considered electric utilities.

Electric Utility Indutry: All enterprises engaged in the production and/or distribution of electricity for use by the public, including investor owned, cooperatively owned, and government-owned electric utilities (the latter includes municipal systems, Federal agencies, state projects, and public power districts), and, where the data are not separable, those industrial plants contributing to the public supply.

Electromagnetic: Of or pertaining to the magnetic forces produced in a surrounding medium by the flow of current in a circuit.

Electromagnetic Radiation: A travelling wave motion resulting from changing electric or magnetic fields. Familiar electromagnetic radiations range from x-rays (and gamma rays) of short wavelength, through the ultraviolet, visible, and infrared regions, to radar (microwave) or radio waves of relatively long wavelength. All electromagnetic radiations travel in a vacuum with the velocity of light.

Electron: An elementary particle with a unit negative charge. Electrons surround the positively charged nucleus and determine the chemical properties of the atom.

Embedded Cost: Monies already spent for investment in plant and operating expenses. Embedded cost may be adjusted or normalized on the basis of known changes that occur during the period under consideration. For example, a new labor contract executed during the period under consideration would further increase labor costs by a known amount. On the other hand, when it is known that certain expenses will not recur in the near future, those expenses should not be considered embedded costs.

Emergency: Any abnormal system condition which required immediate manual or automatic action to prevent loss of load, equipment damage, or tripping of system elements which might result in cascading and to restore system operation to meet the Minimum Operating Reliability Criteria.

Emergency Assistance Energy: Energy delivered to other utilities in situations of unplanned, forced outages to their generation or transmission facilities.

Emergency notice: A notice issued by the CAISO when the system reliability of the CAISO controlled grid is in danger of instability, voltage collapse, or under-frequency caused by transmission or generation trouble in the CAISO control area, or events outside of the CAISO control area that could result in a cascade of events throughout the WSCC grid.

• Stage 1: Actual or anticipated operating reserves are less than WSCC minimum operating reserve criteria.
• Stage 2: Actual or anticipated operating reserves are less than or equal to five percent (5%).
• Stage 3: Actual or anticipated operating reserves are less than or equal to 1 1/2%

EMS: see Energy Management System

Encoder: A device which converts a meter reading into a form suitable for communicating to a remote central location or portable recording device.

End-Use Customer: A residential, commercial, agricultural, or industrial customer in the electric industry who buys electric power to be consumed as a final product (not for resale).

Energized System (or Facilities) : A system under load (supplying energy to load) or carrying rated voltage and frequency, but not supplying load.

Energy: The capacity for doing work as measured by the capability of doing work (potential energy) or the conversion of this capability to motion (kinetic energy). Energy has several forms, some of which are easily convertible and can be changed to another form useful for work. Most of the world's convertible energy comes from fossil fuels that are burned to produce heat that is then used as a transfer medium to mechanical or other means in order to accomplish tasks. Electrical energy is usually measured in kilowatthours or megawatthours, while heat energy is usually measured in British thermal units (BTU) or joules.

Energy Charge: That portion of the charge for electric service based upon the electric energy (kWh) consumed or billed. The charge is generally expressed as a mills/kWh, ¢/kWh, or $/MWh value.

Energy Component: Part of a firm power rate; expressed in mills per kilowatt-hour (kWh). Applied to each kWh made available to each customer.

Energy Conservation: The more efficent use of energy resources. Energy conservation seeks to reduce energy invested per unit of product output, service performed, or benefit received through waste reduction. Energy conservation and energy use reduction are not synonymous.

Energy Costs: Costs, such as for fuel, that are related to and vary with energy production and consumption.

Energy Deliveries: Energy generated by one electric utility system and delivered to another system through one or more transmission lines.

Energy, Dump: Energy generated in hydroelectric plants by water that cannot be stored or conserved and which energy is in excess of the needs of the electric system producing the energy.

Energy, Economy: Energy produced and supplied from a more economical source in one system, for that being produced or capable of being produced by a less economical source in another system (e.g., hydroelectric for oil fired generation).

Energy Effects: The changes in aggregate electricity use (measured in megawatthours) for customers that participate in a utility DSM program. Energy Effects should represent changes at the consumer meter (i.e., exclude transmission and distribution effects) and reflect only activities that are undertaken specifically in response to utility-administered programs, including those activities implemented by third parties under contract to the utility. To the extent possible, Energy Effects should exclude non-program related effects such as changes in energy usage attributable to nonparticipants, government-mandated energy efficiency standards that legislate improvements in building and appliance energy usage, changes in consumer behavior that result in greater energy use after initiation in a DSM program, the natural operations of the marketplace, and weather and business cycle adjustments.

Energy Efficiency: Refers to programs that are aimed at reducing the energy used by specific end-use devices and systems, typically without affecting the services provided. These programs reduce overall electricity consumption (reported in megawatthours), often without explicit consideration for the timing of program-induced savings. Such savings are generally achieved by substituting technically more advanced equipment to produce the same level of end-use services (e.g. lighting, heating, motor drive) with less electricity. Examples include high-efficiency appliances, efficient lighting programs, high-efficiency heating, ventilating and air conditioning (HVAC) systems or control modifications, efficient building design, advanced electric motor drives, and heat recovery systems.

Energy, Firm: Electric energy which is intended to have assured availability to the customer to meet all or any agreed upon portion of his load requirements.

Energy, Fuel Replacement: Electric energy generated at a hydroelectric plant as a substitute for energy which would otherwise have been generated by a thermal - electric plant.

Energy, Interchange: Electric energy received by one electric utility system usually in exchange for energy delivered to the other system at another time. Interchange energy is to be distinguished from a direct purchase or sale, although accumulated energy balances are sometimes settled for in cash.

Energy Loss: The difference between energy input and output as a result of transfer of energy between two points.

Energy, Maintenance: Energy delivered to other utilities during scheduled maintenance outages to their generation or transmission facilities.

Energy Management System (EMS): A computer-controlled system used by electric utility operators to monitor the real-time performance of the various elements of an electric system and to control generation and transmission facilities.

Energy, Off Peak: Electric energy supplied during periods of relatively low system demands as specified by the supplier.

Energy, On Peak: Electric energy supplied during periods of relatively high system demands as specified by the supplier. In the WSCC, on peak hours are defined as Monday through Saturday, HE 0700 to HE 1100, excluding designated holidays.

Energy Rate: See Energy Charge.

Energy Receipts: Energy generated by one electric utility system and received by another system through one or more transmission lines.

Energy, Renewable: Any energy resource which has recently originated in the sun, including direct and indirect solar radiation and intermediate solar energy forms such as wind, ocean thermal gradients, ocean currents and waves, hydropower, photovoltaic energy, products of photosynthetic processes, organic wastes, and others.

Energy Source: The primary source that provides the power that is converted to electricity through chemical, mechanical, or other means. Energy sources include coal, petroleum and petroleum products, gas, water, uranium, wind, sunlight, geothermal, and other sources.

Energy, Surplus: Energy generated that is beyond the immediate needs of the producing system. This energy is frequently obtained from spinning reserve and sold on an interruptible basis.

Energy Used By Producer: Energy generated and used by certain large industrial companies that own electric generating facilities whose output is not available to the public, but is included with the generation of electric utilities by the Federal Agency Regulatory Commission as part of the electric utility industry's generation.

Environmental Assessment: A concise written document prepared by a Federal agency that briefly provides sufficient evidence and analysis for determining whether to prepare an environmental impact statement or finding of no significant impact.

Environmental Impact Statement (EIS): A detailed written document prepared by a Federal agency on the environmental impacts of a proposed action that significantly affects the quality of the human environment. An environmental impact statement normally requires 2 to 2 ½ years to complete and is a tool for planning and decision- making and is a requirement of the National Environmental Policy Act.

Environmental Planning: A systematic process of analyzing need and environment and organizing their components into a plan which serves the need while minimizing adverse environmental effects.

EPA: Environmental Protection Agency

EPAct: Energy Policy Act of 1992

EPAMP: (Western’s) Energy Planning and Management Program

EPAMP-EIS: The EIS conducted for EPAMP

EPM-EIS: (Western’s Salt Lake City Area Integrated Projects) Electric Power Marketing EIS

EPRI: Electric Power Research Institute - an organization, financially supported by electric utilities, that conducts research into electric power issues.

Equity Capital: The sum of capital from retained earnings and the issuance of stocks.

Equivalent Barrel of Oil: A standard measure of heat content equivalent to the number of Btu in a representative barrel of oil, about 6,250,000 Btu.

EWG: Exempt Wholesale Generator

Excitation: The power required to energize the magnetic field of generators in an electric generating station, and transformers.

Exciter: A source, usually a direct-current generator, of current for initiating or developing a magnetic field in a generator.

Expenditure: The incurrence of a liability to obtain an asset or service.

Exports, Net Electric: Exports of electical energy in excess of imports across a political boundary or boundaries, being "Gross Out" less "Gross In" during a stated period. This term is applied also to power flow of load at stated times.

Extra High Voltage (EHV): Descriptive of transmission lines with voltage levels higher than high voltage (HV) but lower than Ultra High Voltage (UHV) levels. EHV is generally considered to range from the 345-kilovolt class or higher.

Facility: An existing or planned location or site at which prime movers, electric generators, and/or equipment for converting mechanical, chemical, and/or nuclear energy into electric energy are situated, or will be situated. A facility may contain more than one generator of either the same or different prime mover type. For a cogenerator, the facility includes the industrial or commercial process.

Facilities Charge: An amount to be paid by the customer in a lump sum, or periodically as reimbursement for facilities furnishes. The charge may include operation and maintenance as well as fixed costs.

Fault: An unintentional short circuit in a power system, due to a breakdown in insulation and causing abnormal current flow. When the fault current flows in ground, the fault is called a Ground Fault (e.g., tree branch in the line or broken conductors that contact the ground or other conductors.

Fault Locator: A device or system that automatically indicates where a Fault occurred on a transmission line to expedite the dispatch of repair crews.

Federal Energy Regulatory Commission (FERC): A quasi-independent regulatory agency within the Department of Energy having jurisdiction over interstate electricity sales, wholesale electric rates, hydroelectric licensing, natural gas pricing, oil pipeline rates, and gas pipeline certification. A commission that has the authority to confirm, approve, and place in effect on a final basis, to remand, or disapprove power transmission rates developed by Western and other electric utilities. Formerly the Federal Power Commission (FPC).

Federal Power Act: Enacted in 1920 and amended in 1935, the Act consists of three parts. The first part incorporated the Federal Water Power Act administered by the former Federal Power Commission, whose activities were confined almost entirely to licensing non-Federal hydroelectric projects. Parts II and III were added with the passage of the Public Utility Act. These parts extended the Act's jurisdiction to include regulating the interstate transmission of electrical energy and rates for its sale as wholesale in interstate commerce. The Federal Energy Regulatory Commission is now charged with the administration of this law.

Federal Power Commission: The predecessor agency of the Federal Energy Regulatory Commission. The Federal Power Commission (FPC) was created by an Act of Congress under the Federal Water Power Act on June 10, 1920. It was charged originally with regulating the electric power and natural gas industries. The FPC was abolished on September 20, 1977, when the Department of Energy was created. The functions of the FPC were divided between the Department of Energy and the Federal Energy Regulatory Commission.

Feeder: A line from a generating plant or an interchange point between a transmission system and a load or distribution system.

FERC: See Federal Energy Regulatory Commission.

Firm Gas: Gas sold on a continuous and generally long-term contract.

Firm Obligation: A commitment to supply electric energy or to make capability available at any time specified during the period covered by the commitment.

Firm Power: Power or power producing capacity intended to be available at all times during the period covered by a guaranteed commitment to deliver, even under adverse conditions, except for reasons of certain uncontrollable forces or continuity of service provisions. (See Energy, Firm).

Firm Transmission Service: Point-to-point transmission service that is reserved and/or scheduled for a term of one year or more and that is of the same priority as that of the Transmission Provider's firm use of the transmission system. Firm Transmission service that is reserved and/or scheduled for a term of less than one year shall be considered Short-Term Firm Transmission Service for the purposes of service liability.

Firming Power: Power Western will purchase up to the SHP level. This type of purchase is included in the firm power rate.

Firming Purchases, WRP: Power purchased by Western or the Contractor above the AHP level up to the Contractor's CROD. This purchase is on a pass-through cost basis.

Fission: The splitting of a heavy nucleus into two parts (which are nuclei of lighter elements), accompanied by the release of a relatively large amount of energy and frequently one or more neutrons.

Flash over: A disruptive discharge through the air around or over the surface of an insulator. Can result from a lightning surge on a transmission line.

Flue Gas Desulfurization Unit (Scrubber): Equipment used to remove sulfur oxides from the combustion gases of a boiler plant before discharge to the atmosphere. Chemicals, such as lime, are used as the scrubbing media.

Flue Gas Particulate Collectors: Equipment used to remove fly ash from the combustion gases of a boiler plant before discharge to the atmosphere. Particulate collectors include electrostatic precipitators, mechanical collectors (cyclones), fabric filters (baghouses), and wet scrubbers.

Flux: The lines of force of a magnetic or electrostatic field.

Fly Ash: Particle matter from coal ash in which the particle diameter is less than one tenth of a millimeter. Fly ash is removed from the flue gas using flue gas particulate collectors such as fabric filters and electrostatic precipitators.

Forced Outage: The shutting down of a generating unit for emergency reasons. Generating units not in operation due to breakdowns, storms or other unplanned occurances.

Forebay: The impoundment immediately above a dam or hydroelectric plant intake structure.

Fossil Fuel: Any naturally occurring organic fuel, such as petroleum, coal, and natural gas.(See Conventional Fuels)

Fossil Fuel Powerplant: A powerplant that uses fossil fuel as a fuel source. A plant using coal, petroleum, or gas as its source of energy.

FPA: Federal Power Act

FR: Federal Register

Francis-type Unit (Francis Turbine): A hydraulic turbine using vanes to drive generating equipment. Water enters the unit at a right angle to the vanes and the turbine's center line.

FRC - Frequency Response Characteristic: For any change in generation/load balance in an interconnection, a frequency change occurs. FRC is how any system (control area) responds to this change during any imbalance resulting from a sudden loss of load or generation. System frequency does not return to its pre-disturbance level until the control area experiencing the imbalance corrects its imbalance.

FRN: Federal Register Notice

Frequency: The number of cycles through which an alternating current passes per second. Frequency has been generally standardized in the United States electric utility industry at 60 cycles per second (60 hertz).

Frequency Deviation: A change in system frequency from one moment to the next

Frequency Error: The difference between the actual and scheduled Interconnection frequency

Frequency Responsive Reserve (FRR): The portion of Operating Reserve that is expected to respond to Frequency Deviations within the Frequency Responsive Reserve Activation Period.

Frequency Responsive Reserve Activation Period:The period after a large frequency deviation in which Frequency Responsive Reserve (FRR) must be provided.

FRS: Frequency Response Standard.

FTE: Full-time equivalent. Represents one full-time employee.

FTR: Firm Transmission Rights

Fuel for Generation: Any substance that can be burned to produce heat; also, materials that can be fissioned in a chain reaction to produce heat. Includes all types of fuel (solid, liquid, gaseous, and nuclear) used exclusively for the production of electric energy. Fuel for other purposes, such as building heating or steam sales, is excluded.

Fuel Adjustment Clause: A clause in a rate schedule that provides for an adjustment of the customer's bill if the cost of fuel at the supplier's generating stations varies from a specified unit cost.

Fuel Elements (Nuclear): A rod, tube, plate, or other geometrical form into which nuclear fuel is fabricated for use in a reactor. Also referred to as a Fuel Assembly.

Fuel Cell: A system which converts the chemical energy of a fuel directly to direct current (DC) electricity without intermediate combustion or thermal cycles.

Fuel Expenses : These costs include the fuel used in the production of steam or driving another prime mover for the generation of electricity. Other associated expenses include unloading the shipped fuel and all handling of the fuel up to the point where it enters the first bunker, hopper, bucket, tank, or holder in the boiler house structure.
(Units most commonly used by electric utility companies)

Nuclear:

Cents per million Btu or mills per kilowatt hour: calculated on a fuel-cycle, which normally lasts 5 to 6 years, consists of all the steps associated with procurement, use and disposal of nuclear fuel; the cost (including interest charges) of each step must be accounted for in computing total fuel costs.

Oil:

Dollars per 42-gallon barrel (bbl) used for fuel oil , crude oil, and diesel oil, and small amounts of tar and gasoline.

Cents Per Million BTU Consumed:

Since coal is purchased on the basis of its heat content, its cost is measured in units of total cost of fuel consumed/total Btu content (in millions) of fuel consumed.

Coal:

Dollars per (short) ton: used for bituminous and anthracite coal and relatively small amounts of lignite and wood

Gas:

Cents per thousand cubic feet (Mcf) : used for natural, manufactured, mixed, and waste gas. Frequently expressed as cost per therm (100,000 Btu).

Fuel Replacement: (See Energy, Fuel Replacement).

Fuel Reprocessing (Nuclear): The processing of reactor fuel to recover the unused fissionable material.

Full-Forced Outage: The net capability of main generating units that are unavailable for load for emergency reasons.

Fuse: A protective device that consists of metal that melts under heat produced by an over-current condition, thereby breaking the circuit.

Fusion: The formation of a heavier nucleus from two lighter ones with the attendent release of energy.

FY: Fiscal year - Western's fiscal year runs from October 1 of a year through September 30 of the following year.

GADS: Generating Availability Data System (a NERC database set)

Gas: A fuel burned under boilers and by internal combustion engines for electric generation. These include natural, manufactured, and waste gas.

Gas Turbine Plant: A plant in which the prime mover is a gas turbine. A gas turbine consists typically of an axial-flow air compressor, one or more combustion chambers, where liquid or gaseous fuel is burned and the hot gases are passed to the turbine and where the hot gases expand to drive the generator and are then used to run the compressor.

Combined Cycle: A gas turbine installation using waste heat boilers to capture exhaust energy for steam generation

Regenerative Cycle: a simple cycle gas turbine to which has been added a heat exchanger to warm the incoming combustion air with heat from the exhaust gasses to increase thermal efficiency.

Simple Cycle: Mechanically, the gas turbine is a very simple engine, consisting of a compressor section which pumps the air for combustion, and a combustion section where the compressed air is mixed with natural gas or oil and burned. The air, in turn, expands with the products of combustion and attains a higher temperature and pressure. This expanded mixture of air and gas then impinges on turbine blades attached to the same shaft as that of the compressor section, thus providing the power required to rotate the combustion air compressor. After the hot gasses pass through the compressor turbine, they go into the power turbine, where the shaft power is used to turn the generator or other powerplant equipment. (Sometimes referred to as a combustion turbine.)

GCD: Glen Canyon Dam (and power plant)

GCD-EIS: the Operation of Glen Canyon Dam EIS prepared by the Bureau of Reclamation

GCES: Glen Canyon Environmental Studies

GCMRC: Grand Canyon Monitoring and Research Center.

GCP Act (GCPA): Grand Canyon Protection Act of 1992

General Plant: A group of utility plant accounts not includible in the other functional utility plant accounts. Includes: Land and Land Rights, Structures and Improvements, Office Furniture and Equipment, Transportation Equipment, Stores Equipment, Tools, Shop and Garage Equipment, Laboratory Equipment, Power Operated Equipment, Communication Equipment, Miscellaneous Equipment, and Other Tangible Property.

Generating Station (Generating Plant or Power Plant): A station at which prime movers, electric generators, and auxiliary equipment are used for converting mechanical, chemical, and/or nuclear energy into electric energy.

Generating Unit: Any combination of physically connected generator(s), reactor(s), boiler(s), combustion turbine(s), or other prime mover(s) operated together to produce electric power.

Generation (Electricity): The process of producing electric energy by transforming other forms of energy; also, the amount of electric energy produced, expressed in watt-hours (Wh).

Generation, Gross: The total amount of electric energy produced by the generating units at a generating station or stations, measured at the generator terminals.

Generation, Net: Gross generation less the electric energy consumed at the generating station for station use.

Generation Reserve Margin: Reserve Capacity

Generator: In power systems, the machine which converts mechanical energy to electrical energy.

Geothermal: An electric generating station in which the prime mover is a steam turbine. The steam is generated in the earth by heat from the earth's magma.

Hydroelectric: An electric generating station in which the prime mover is a water wheel driven by falling water.

Nuclear: An electric generating station in which the prime mover is a steam turbine. The steam is generated in a reactor by heat from the fissioning of nuclear fuel.

Steam (Conventional): An electric generating station in which the prime mover is a steam turbine. The steam is generated in a boiler by heat from burning fossil fuels.

Generator, Induction: A nonsynchronous AC generator identical in construction with an AC motor, and which is driven above synchronous speed by external sources of mechanical power.

Generator Nameplate Capacity: The full-load continuous rating of a generator, prime mover, or other electric power production equipment under specific conditions as designated by the manufacturer. Installed generator nameplate rating is usually indicated on a nameplate physically attached to the generator.

Generator, Synchronous: A machine that generates an alternating current when its armature field is rotated within the armature winding. The output frequency is exactly proportional to the speed at which the generator is driven.

Geothermal Plant: A plant in which the prime mover is a steam turbine. The turbine is driven either by steam produced from hot water or by natural steam that derives its energy from heat found in rocks or fluids at various depths beneath the surface of the earth. The energy is extracted by drilling and/or pumping. The cost of producing electicity with geothermal resources depends on the resource temperature, plant size, plant efficiency, production well depth, and production well flow rate.

Gigawatt (GW): One billion watts.

Gigawatthour (GWh): One billion watthours.

Glen Canyon Dam: The dam on the Colorado River which forms Lake Powell. One of several dams and powerplants that make up the CRSP.

Good Utility Practice: Any of the practices, methods, and acts engaged in or approved by a significant portion of the electric utility industry during the relevant time period, or any of the practices, methods, and acts which, in the exercise of reasonable judgment in light of the facts known at the time the decision was made, could have been expected to accomplish the desired result of the lowest reasonable cost consistent with good business practices, reliability, safety and expedition. Good Utility Practice is not intended to be limited to the optimum practice, method, or act to the exclusion of all others, but rather to be acceptable practices, methods, or acts generally accepted in the region and consistently adhered to by the Transmission Provider.

Governor: The device which gauges the speed of a Turbine and activates measures to control the speed.

GPM: gallons per minute

Greenhouse Effect: The increasing mean global surface temperature of the earth caused by gases in the atmosphere (including carbon dioxide, methane, nitrous oxide, ozone, and chlorofluorocarbon). The greenhouse effect allows solar radiation to penetrate but absorbs the infrared radiation returning to space.

Grid: The name given to an interconnected system of electric transmission lines and associated equipment for the movement or transfer of electric energy in bulk between points of supply and points of demand. The layout of an electrical distribution system.

Gross Generation: The total amount of electric energy produced by the generating units in a generating station or stations.

Gross, Net: Generation less kilowatt hours consumed out of gross generation for station use.

Ground: A conducting connection between an electric circuit and earth.

Grounded System: A system of conductors in which at least one conductor (usually in the middle wire or neutral point of transformer or generator windings) is intentionally grounded either solidly or through a current-limiting device.

Grounding Switch: A switch by means of which a circuit may be connected to ground.

Guy: A steel wire used to support or strengthen a structure.

GW: See Gigawatt; 1,000 Megawatts (MW); 1,000,000,000 watts.

GWh: See Gigawatthour.

Hand Line: Non-metallic rope and small pully for raising and lowering tools and equipment to line workers.

Hazardous Material: A substance or material which has been determined by the Secretary of Transportation to be capable of posing an unreasonable risk to health, safety, and property when transported in commerce and which has been so designated.

Hazardous Voltage: Above 600 volts.

HE: Hour ending. For example, HE 0700 means the hour beginning at 6 a.m. and ending at 7 a.m.

Head: The dam creates a "head" (height from the power plant turbine to the water surface behind the dam). The amount of head, coupled with the volume of water flowing through the turbines, determines how much energy a hydro powerplant produces. When head and flow are increased, power output increases. The combination of "head" and "flow" produces energy.

Head, Critical: The head at which full-gate output of the turbine equals the nameplate generator capacity.

Head Differential: Head differential is the force per unit area exerted by a column of liquid at a certain height compared to some lower point. The higher the head; the better able it is to produce hydroelectric generation.

Head, Gross: The difference in elevations between water surfaces of the forebay and tailrace under specific conditions. Gross head usually refers to the difference between normal full pool and average tailwater.

Head, Net (Effective Head): Gross head less all hydraulic losses except those attributable to the turbine.

Heat Exchanger: A device that transfers heat from one material, such as gas or water, to another substance with no direct contact between the two materials.

Heat Pump: A year-round air conditioning system employing refrigeration equipment in a manner which enables usable heat to be supplied to a space during the winter period and by reversing the operation cycle to extract heat from the same space during the summer period. When operating as a heating system, heat is absorbed from an outside medium (either air, water, or the earth) and this heat together with the heat equivalent of the work of compression is supplied to the space to be heated. When operating on the cooling cycle, heat is absorbed from the space to be cooled, and this heat together with the heat equivalent of the work of compression is rejected to the outside medium.

Heat Rate: A measure of the thermal efficiency of a generating station. Generally expressed in Btu per net kilowatt-hour. It is computed by dividing the total Btu content of fuel burned for electric generation by the resulting net kilowatt-hour generation.

Heating System: Energy Efficiency program promotion aimed at improving the efficiency of the heating delivery system, including replacement, in the residential, commercial, or industrial sectors.

Heavy Oil: The fuel oils remaining after the lighter oils have been distilled off during the refining process. Except for start-up and flame stabilization, virtually all petroleum used in steam plants is heavy oil.

Hertz (Hz): Frequency in Cycles per second.

H-Frame: A wooden pole structure commonly used for voltages from 69 thru 230 kV, designation originates from appearance of the structure which has a double-plank cross arm.

High Side: The higher voltage electrical system of two systems connected by a transformer.

Hockey Stick Bid: A bid in a market-clearing price electicity auction that offers most capacity at the marginal cost and the remainder at much higher costs. This is a bidding strategy meant to increase the market-clearing price paid for all capacity.

Horsepower (hp): A standard unit of power equal to 746 watts.

Hot Line Order: A statement with documentation from an operations supervisor to a job supervisor that the automatic reclosing is turned off and that equipment covered by a hot line order will not be re-energized until the conditions stated on the hot line order are met. This allows specific work to be done on or near a line or other equipment without requiring that it be disconnected from all source of electrical energy. The equipment is considered to be energized or “hot.”

Hot Stick: An insulated stick used for repair work on live lines, and for installing protective grounding.

Hour-Ahead Market: The electric power futures market that is established 1-hour before delivery to End-Use Customers.

Hourly Non-Firm Transmission Service: Point-to-point transmission that is scheduled and paid for on an as-available basis and is subject to interruption.

Hydraulic Turbines: Turbines activated by the flow of water under pressure; the prime mover or driving force of an electric generator.

Hydro: A term used to identify a type of generating station, power, or energy output in which the prime mover is driven by water power. A hydroelectric plant, for example, is an electric power plant in which the energy of falling water is converted into electricity by turning a turbine generator.

Hydroelectric Plant: A plant in which the turbine generators are driven by falling water.

Hysteresis: Loss in the core of a transformer due to molecular friction.

IBWC: International Boundary and Water Commission (Operators of the Falcon and Amistad hydroelectric plants on the Rio Grande River in Texas.)

Impedance: A characteristic of an electric Circuit which determines its hindrance to the flow of electricity. More specifically, at a given applied Voltage (E) impedance (Z) determines the resulting Current (I), or E=IZ, which means the higher the impedance, the lower the current. Impedance is mathematically equivalent to the square root of the sum of the Resistance squared and the Reactance squared.

Imports, Net Electric: Imports of electric energy in excess of exports across a political boundary or boundaries, being "Gross In" less "Gross Out" during a stated period. This term applies also to power flow or load at stated times.

Increasing Block Rate: A rate design for a customer class for which the unit charge for electricity increases as usage increases.

Incremental Cost (Energy): The increase in cost of generating or transmitting additional energy above some previously determined base amount.

Incremental Effects: The annual effects in energy use (measured in megawatthours) and peak load (measured in kilowatts) caused by new participants in existing DSM programs and all participants in new DSM programs during a given year. Reported Incremental Effects should be annualized to indicate the program effects that would have occurred had these participants been initiated into the program on January 1 of the given year. Incremental effects are not simply the Annual Effects of a given year minus the Annual Effects of the prior year, since these net effects would fail to account for program attrition, degradation, demolition, and participant dropouts.

Independent Power Producers (IPP): A non-utility.

Indirect Utility Cost: A utility cost that may not be meaningfully identified with any particular DSM program category. Indirect costs could be attributable to one of several accounting cost categories (i.e., Administrative, Marketing, Monitoring & Evaluation, Utility-Earned Incentives, Other). Accounting costs that are known DSM program costs should not be reported under Indirect Utility Cost, rather those costs should be reported as Direct Utility Costs under the appropriate DSM program category.

Inductance: The property of an electric circuit by virtue of which a varying current induces a voltage in that circuit or a neighboring circuit.

Industrial: The industrial sector is generally defined as manufacturing, construction, mining, agriculture, fishing, and forestry establishments (Standard Industrial Classification [SIC] codes 01-39). The utility may classify industrial service using the SIC codes, or based on demand or annual usage exceeding some specified limit. The limit may be set by the utility based on the rate schedule of the utility.

Insulator: An extremely low conductive support for a conductor. It inhibits the flow of current from the conductor to earth or another conductor.

Insulator, Suspension: An insulator made of an extremely low conducting material such as porcelain or glass used to suspend the conductor from the tower or structure. Main parts consist of the cap (upper part made of metal) ; the skirt (middle section made of insulating material); and the ball stem (lower metal portion.) The ball stem connects to the cap of next insulator in a string.

Integrated Demand: The demand usually determined by an integrating demand meter or by the integration of a load curve. It is the summation of the continuously varying instantaneous demands during a specified demand interval.

Integrated Projects: See SLCA/IP.

Integrated Resource Planning: Consideration of both